6.2. Running the Test Suite¶

We use pytest and tox to run tests against all supported Python versions. All test dependencies are resolved automatically.

You can decide to run the complete test suite or only part of it:

To run all tests, use:
```
$ tox
```
If you have not all Python interpreters installed on your system it will probably give you some errors (InterpreterNotFound). To avoid such errors, use:
```
$ tox --skip-missing-interpreters
```
It is possible to use one or more specific Python versions. Use the -e option and one or more abbreviations (py37 for Python 3.7, py38 for Python 3.8 etc.):
```
$ tox -e py37
$ tox -e py37,py38
```
To get a complete list and a short description, run:
```
$ tox -av
```
To run only a specific test, pytest requires the syntax TEST_FILE::TEST_FUNCTION.

For example, the following line tests only the function test_immutable_major() in the file test_bump.py for all Python versions:
```
$ tox -e py37 -- tests/test_bump.py::test_should_bump_major
```
By default, pytest prints only a dot for each test function. To reveal the executed test function, use the following syntax:
```
$ tox -- -v
```
You can combine the specific test function with the -e option, for example, to limit the tests for Python 3.7 and 3.8 only:
```
$ tox -e py37,py38 -- tests/test_bump.py::test_should_bump_major
```

Our code is checked against formatting, style, type, and docstring issues (black, flake8, mypy, and docformatter). It is recommended to run your tests in combination with checks, for example:

$ tox -e checks,py37,py38